Conventional solid dosage forms for veterinary drugs, such as tablets and capsules, can be expelled by the animal, and multiple dosing is often difficult because the animal learns to resist the dosing procedure. While some drugs can be administered in liquid form, others are unstable in an aqueous medium and cannot be provided as a conventional liquid. Accordingly, it is an object of this invention to provide a new delivery system for veterinary drugs.
The invention provides a palatable oral delivery system suitable for drugs that are unstable in an aqueous medium, and which animals will readily consume. In addition, the invention provides an easily handled and calibrated drug delivery composition that is easy to manufacture and use, and which is readily accepted by animals. The composition described and claimed herein can also be processed as a pourable liquid, but becomes a semisolid medium for ease of administration, proper texture, and uniformity of the drug or drugs to be dosed. This composition can be optionally flavored, to further improve its acceptance by animals.
Formulations comprising antibiotics in oil bases for veterinary applications are known, and include both liquid and solid compositions. For example, British Patent No. 1,089,523 relates to a veterinary composition for treating inflammation of mammary glands in dairy animals. This composition is for topical use, and comprises an antibiotic, a hydrophobic viscous or gel base (e.g., a petroleum-based mineral oil gelled with an aluminum soap, such as commercial aluminum monostearate), and at least 10 percent by weight of a solid, finely divided physiologically innocuous non-gelling water soluble compound of average particle size below 150 microns (e.g., sugar or salt).
The formulation described in the British ''523 patent is not for oral use because the soap (e.g. aluminum stearate) makes the preparation substantially un-palatable. Furthermore, the mineral oil base is a distillate of petroleum, which poses a digestive problem if orally ingested.
Various triglycerides are used in cream and ointment formulations, but are not known in oral dosage forms, nor in combination with silicon dioxide and fixed oils as a pharmaceutical vehicle. Similarly, silicon dioxide colloidal N.F. (cabosil) is not known in orally administrable, paste form. Colloidal silicone dioxide is an extremely fine non-gritty powder which is known as a solid thickener or suspending agent, and has been used as a diluent in tablets.
An antibiotic in hydrophobic colloidal silicon for veterinary administration is disclosed in Japanese Patent No. 60-169431. However, the disclosed formulation is not suitable for oral administration and the reference does not disclose the possibility of incorporating colloidal silicone with triglycerides.